Scurtă descriere de design

We received the initial enquiry for this load cell from a regular customer, who are offshore oil and gas system integrators. The load cells were required to be installed within a chain stopper, on a oil service platform.

These chain stopper load cells were to be designed as a retrofit solution, so we had a limited space available for the load cells. There were also some existing mounting points that were available, which we had to make the load cell fit, to aid expedient installation. The detailed criteria we had to meet is shown below, but the general brief was that the load cell had to be robust and should have an in service life, exceeding 10 years.

The main criteria we were given was as follows:-

Overall height to be 117mm.

To be supplied with a mounting base, for simple installation

Environmental protection needed to be IP68

Accuracy to be <±5%

Full stainless steel construction essential

All critical load bearing materials must have full certificate traceability

Proof testing and final calibration to be witnessed by Lloyds Register of Shipping

Caracteristici

Load Cell manufactured from 17-4PH stainless steel

Cover and mounting base manufactured from 316 stainless steel

Load Cell had full welded construction

Low Height (only 117mm high, including mounting base)

IP68 sealing, suitable for full submersion

Sub-sea connector and cable assembly

Supplied calibrated, with a calibration certificate, traceable to UKAS, with Lloyds witnessing

Specificații

Rated Load (RL):

550 tonne

Proof Load:

715 tonne

Ultimate Breaking Load:

>2200 tonne

Output:

2.2mV/V nominally

Accuracy:

<±5% of Rated Load

Non-Repeatability:

<±0.2% of Rated Load

Excitation Voltage:

10vdc recommended, 15vdc maximum

Bridge Resistance:

350Ω

Insulation Resistance:

>100MΩ @ 500vdc

Operating Temperature Range:

-20 to +70°C

Compensated Temperature Range:

-10 to +60°C

Zero Temperature Coefficient:

<±0.01% of Rated Load/°C

Span Temperature Coefficient:

<±0.01% of Rated Load/°C

Environmental Protection Level:

IP68

Connection Type:

Integral Wetcon sub-sea connector & mating 20m cable assembly

Modelare 2D

Modelare 3D PDF

Rezultatele testului

Observații

The dimensions were a limiting factor with this load cell design. Normally a compression load cell of this capacity would be at least 3-5 time higher to achieve what we would normally expect as a reasonable load cell accuracy. Fortunately, the accuracy requirements for this application were not quite as rigid as we would normally work to.

The load cells performed well and were originally supplied in 1994. In 2004, the end customer then approved another system to be considered, with our load cells being specified. These were supplied promptly to the same specification as the originals, which we understand are still operating well.

LCM Systems manufacture a large and varied range of custom design and standard product variant compression load cells. These have been supplied as 1off products, or as part of an instrumentation system. Many of these products are supplied with built in analogue signal conditioning, digital outputs or with wireless telemetry.

Please contact us to discuss any special compression load cell requirements you may have.